139453 - Strain distribution.pdf (261.54 kB)
Strain distribution of dowel-type connections reinforced with self-tapping screws
journal contribution
posted on 2023-05-20, 15:12 authored by Cong ZhangCong Zhang, Harris, R, Chang, WSCurrent limited guidance on the selection of screws together with undefined design specifications restricts the effectiveness of self-tapping screws as reinforcement on timber members to control crack propagation. Using digital image correlation (DIC), this study visualized the surface strain distribution of screw-reinforced dowel-type connections to understand the influence of thread configuration and screw-to-dowel distance on controlling crack propagation. The experiment was based on single-dowel embedment tests using 16- and 20-mm-diameter steel dowels. Three thread lengths (0%, 33%, and 100% thread) and six screw-to-dowel distances (0.5d, 0.75d, 1d, 1.5d, 2d, and 4d) were investigated. Results show that a screw with 33% thread on the point end can be as effective as screws with 100% thread to control crack propagation under the same geometrical parameters of the connections. Results also reveal that a screw placed further from the dowel (e.g., at 2d distance) can delay the crack-controlling effect. Self-tapping screws placed at 2d can still improve the embedment strength and ductility; however, further doubling this distance (4d) did not enhance the embedment strength, but a higher ductility was still achieved.
History
Publication title
Journal of Materials in Civil EngineeringVolume
32Article number
04019319Number
04019319Pagination
1-19ISSN
0899-1561Department/School
School of Architecture and DesignPublisher
Asce-Amer Soc Civil EngineersPlace of publication
1801 Alexander Bell Dr, Reston, USA, Va, 20191-4400Rights statement
Copyright 2020. This material may be downloaded for personal use only. Any other use requires prior permission of the American Society of Civil Engineers. This material may be found at http://dx.doi.org/10.1061/(ASCE)MT.1943-5533.0002883Repository Status
- Open